Arrhenatherum elatius - (L.) J.& K. Presl
Tall Oatgrass
Other Common Names: tall oatgrass
Taxonomic Status: Accepted
Related ITIS Name(s): Arrhenatherum elatius (L.) P. Beauv. ex J. Presl & C. Presl (TSN 41443)
Unique Identifier: ELEMENT_GLOBAL.2.146457
Element Code: PMPOA0L010
Informal Taxonomy: Plants, Vascular - Flowering Plants - Grass Family
Kingdom Phylum Class Order Family Genus
Plantae Anthophyta Monocotyledoneae Cyperales Poaceae Arrhenatherum
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Concept Reference
Concept Reference: Kartesz, J.T. 1994. A synonymized checklist of the vascular flora of the United States, Canada, and Greenland. 2nd edition. 2 vols. Timber Press, Portland, OR.
Concept Reference Code: B94KAR01HQUS
Name Used in Concept Reference: Arrhenatherum elatius
Conservation Status

NatureServe Status

Global Status: GNR
Global Status Last Changed: 22Mar1994
Rounded Global Status: GNR - Not Yet Ranked
Nation: United States
National Status: NNA
Nation: Canada
National Status: NNR (27Aug2016)

U.S. & Canada State/Province Status
United States Alabama (SNA), Alaska (SNA), Arizona (SNA), Arkansas (SNA), California (SNA), Colorado (SNA), Connecticut (SNA), Delaware (SNA), District of Columbia (SNA), Georgia (SNR), Hawaii (SNA), Idaho (SNA), Illinois (SNA), Indiana (SNA), Iowa (SNA), Kansas (SNA), Kentucky (SNA), Maine (SNA), Maryland (SNA), Massachusetts (SNR), Michigan (SNA), Minnesota (SNA), Mississippi (SNA), Missouri (SNA), Montana (SNA), Nebraska (SNA), Nevada (SNA), New Hampshire (SNA), New Jersey (SNA), New Mexico (SNA), New York (SNA), North Carolina (SNA), Ohio (SNA), Oregon (SNA), Pennsylvania (SNA), Rhode Island (SNA), South Dakota (SNA), Tennessee (SNA), Utah (SNA), Vermont (SNA), Virginia (SNA), Washington (SNA), West Virginia (SNA), Wisconsin (SNA), Wyoming (SNA)
Canada British Columbia (SNA), New Brunswick (SNA), Newfoundland Island (SNA), Nova Scotia (SNA), Ontario (SNA), Quebec (SNA)

Other Statuses

NatureServe Global Conservation Status Factors

Other NatureServe Conservation Status Information

U.S. States and Canadian Provinces
Color legend for Distribution Map
NOTE: The distribution shown may be incomplete, particularly for some rapidly spreading exotic species.

U.S. & Canada State/Province Distribution
United States AKexotic, ALexotic, ARexotic, AZexotic, CAexotic, COexotic, CTexotic, DCexotic, DEexotic, GA, HIexotic, IAexotic, IDexotic, ILexotic, INexotic, KSexotic, KYexotic, MA, MDexotic, MEexotic, MIexotic, MNexotic, MOexotic, MSexotic, MTexotic, NCexotic, NEexotic, NHexotic, NJexotic, NMexotic, NVexotic, NYexotic, OHexotic, ORexotic, PAexotic, RIexotic, SDexotic, TNexotic, UTexotic, VAexotic, VTexotic, WAexotic, WIexotic, WVexotic, WYexotic
Canada BCexotic, NBexotic, NFexotic, NSexotic, ONexotic, QCexotic

Range Map
No map available.

Ecology & Life History Not yet assessed
Economic Attributes Not yet assessed
Management Summary Not yet assessed
Population/Occurrence Delineation Not yet assessed
Population/Occurrence Viability
U.S. Invasive Species Impact Rank (I-Rank)
Disclaimer: While I-Rank information is available over NatureServe Explorer, NatureServe is not actively developing or maintaining these data. Species with I-RANKs do not represent a random sample of species exotic in the United States; available assessments may be biased toward those species with higher-than-average impact.

I-Rank: Low/Insignificant
Rounded I-Rank: Low
I-Rank Reasons Summary: Primarily in pastures, roadsides, non-crop areas, cultivated fields, prairies and grasslands. It will displace native species and in some places is taller than the native vegetation but doesn't appear to cause a huge impact. In Oregon, it reduces the amount of native vegetation available for a rare butterfly but it isn't the only non-native causing a problem for the species. Arrhenatherum elatius already occurs in almost every state and doesn't seem to be expanding its local range quickly. It is available for purchase and at one time used in re-vegetation projects. There seems to be good advances in managing this species by mowing multiple times at a height above the native species.
Subrank I - Ecological Impact: Low/Insignificant
Subrank II - Current Distribution/Abundance: Medium
Subrank III - Trend in Distribution/Abundance: Medium/Low
Subrank IV - Management Difficulty: Low/Insignificant
I-Rank Review Date: 24Jun2004
Evaluator: Killeffer, T.
Native anywhere in the U.S?
Native Range: Europe, Northern Africa, Temperate Asia, plus some of the Atlantic Islands - Canary, Madeira and Azores (Weber 2003).

Download "An Invasive Species Assessment Protocol: Evaluating Non-Native Plants for their Impact on Biodiversity". (PDF, 1.03MB)
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Screening Questions

S-1. Established outside cultivation as a non-native? YES
Comments: Kartesz 1999.

S-2. Present in conservation areas or other native species habitat? Yes
Comments: Weber (2003) has it labeled as invasive to natural areas in the Western U.S. Encroaches into remnant prairies (Wilson, no date).

Subrank I - Ecological Impact: Low/Insignificant

1. Impact on Ecosystem Processes and System-wide Parameters:Insignificant
Comments: No perceivable impacts mentioned in literature search. Not a nitrogen fixer (USDA Plants Database 2004).

2. Impact on Ecological Community Structure:Medium/Low significance
Comments: Grass invading grassy areas; sometimes taller than native vegetation(NPS 2001 and Wilson 2001).

3. Impact on Ecological Community Composition:Medium/Low significance
Comments: "Widely considered to suppress shorter and slower growing native species" (Wilson 2001). Displaces natives (NPS 2001). Is not allelopathic (USDA Plants Database 2004).

4. Impact on Individual Native Plant or Animal Species:Medium/Low significance
Comments: A rare northwestern butterfly's habitat is threatened by this species as well as others by reducing the native larval food plants and also obscure or prevent access by adults to nectar plants (McCarthy 2002). Elk don't find it attractive (NPS 2001).

5. Conservation Significance of the Communities and Native Species Threatened:Low significance
Comments: The rare northwestern butterfly has a conservation status rank of G2G3 as of June 2004 (NatureServe).

Subrank II. Current Distribution and Abundance: Medium

6. Current Range Size in Nation:High significance
Comments: Kartesz has it occuring in almost every state (1999).

7. Proportion of Current Range Where the Species is Negatively Impacting Biodiversity:Low significance/Insignificant
Comments: Problem in Oregon and California (McCarthy 2002, Wilson 2001, and Fitzsimmons 1993). Did not find problems reported elsewhere in relation to its impact on biodiversity.

8. Proportion of Nation's Biogeographic Units Invaded:High significance
Comments: Since it occurs in almost every state, the assumption is made that it occurs in most biogeographic units.

9. Diversity of Habitats or Ecological Systems Invaded in Nation:Low significance
Comments: Primarily in pastures, roadsides, non-crop areas, and cultivated fields (Fitzsimmons 1993). Pastures and prairies (Wilson 2001). Grasslands (McCarthy 2002).

Subrank III. Trend in Distribution and Abundance: Medium/Low

10. Current Trend in Total Range within Nation:Medium/Low significance
Comments: Since it occupies most of the U.S., the range is either stable or spreading slightly (Kartesz 1999).

11. Proportion of Potential Range Currently Occupied:Insignificant
Comments: Already occupies most of the U.S. (Kartesz 1999).

12. Long-distance Dispersal Potential within Nation:High significance
Comments: Sold in the trade. Once used in re-vegetation programs for yellow starthistle control (DiTomaso 2004).

13. Local Range Expansion or Change in Abundance:Medium/Low significance
Comments: In California at the Redwood National and State Parks, they are trying to prevent further spread but the rate is unknown (NPS 2001).

14. Inherent Ability to Invade Conservation Areas and Other Native Species Habitats:Medium/Low significance
Comments: The typical habitats it invades are disturbed.

15. Similar Habitats Invaded Elsewhere:High/Low significance
Comments: Weber (2003) Labels it as invasive to natural areas in New Zealand but it is also introduced to South America, Tropical Asia, Southern Africa and Australia.

16. Reproductive Characteristics:Low significance
Comments: The var. bulbosum spreads by rhizomes. Rhizomes produce a corm with each corm capable of producing four to five more corms each with a regenerative bud that sprouts in varying years. High germination percentage for seed. The var. elatius has no corms and does not spread by rhizomes but grow as tufts (Fitzsimmons 1993).

Subrank IV. General Management Difficulty: Low/Insignificant

17. General Management Difficulty:Medium/Low significance
Comments: After four years of mowing twice and removing cut material in late spring at the height of 15 cm in western Oregon, the population of Arrhenatherum elatius was reduced and the growth of native prairie grasses was promoted (Wilson 2001).

18. Minimum Time Commitment:Low significance
Comments: Four years (Wilson 2001).

19. Impacts of Management on Native Species:Insignificant
Comments: The native grasses are well below the mowing height (Wilson 2001).

20. Accessibility of Invaded Areas:Low significance/Insignificant
Comments: Typical habitats are roadsides and pastures where access seems easy but prairies may be more difficult.

Botanical data developed by NatureServe and its network of natural heritage programs (see Local Programs), The North Carolina Botanical Garden, and other contributors and cooperators (see Sources).

  • DiTomaso, J. 2004. Yellow Starthistle Information. Weed Research & Information Center. University of California, Davis, CA. (accessed 2004).

  • Kartesz, J.T. 1994. A synonymized checklist of the vascular flora of the United States, Canada, and Greenland. 2nd edition. 2 vols. Timber Press, Portland, OR.

  • Kartesz, J.T. 1996. Species distribution data at state and province level for vascular plant taxa of the United States, Canada, and Greenland (accepted records), from unpublished data files at the North Carolina Botanical Garden, December, 1996.

  • Kartesz, J.T. 1999. A synonymized checklist and atlas with biological attributes for the vascular flora of the United States, Canada, and Greenland. First edition. In: Kartesz, J.T., and C.A. Meacham. Synthesis of the North American Flora, Version 1.0. North Carolina Botanical Garden, Chapel Hill, N.C.

  • McCarthy, S. 2002. Candidate Assessment and Listing Priority Assignment Form. Polites mardon. Western Washington Fish and Wildlife Office.

  • National Park Service. 2001. Tall Oatgrass, Arrhenatherum elatius, Grass Family. Redwood National Park and State Parks, 1111 Second Street, Crescent City, CA. (accessed 2004).

  • USDA, NRCS. 2004. The PLANTS Database, Version 3.5 ( . National Plant Data Center, Baton Rouge, LA 70874-4490 USA.

  • Weber, E. 2003. Invasive plant species of the world: a reference guide to environmental weeds. CABI Publishing, Cambridge, Massachusetts. 548 pp.

  • Wilson, M. V., and D. L. Clark. 2001. Controlling invasive Arrhenatherum elatius and promoting native prairie grasses through mowing. Applied Vegetation Science 4:129-138. [ or]

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